Oh, youre thinking about the actual death bit. There's a couple of ways to do it easier then holding your breath and hoping the coroner doesn't notice during the autopsy.

Head to a place that's known to be semi-dangerous for whatever reason (a beachfront hotel, mountains, etc). Inform people of your vacation plans, and then dissappear the same way that other people who probably died did. If you're really didcated, go to bear country, leave food out for a bear, and then dump some pre-drawn blood of yours around when a bear shows up and then disappear. Switch countries and never look back. This is a dick move, but if pretending death is the best solution you can find it should work well enough.

If you're just trying to run away, it's actually relatively easy. Sell/trash everything, buy an old car, drive across country, and start completely over without ever telling anyone where you went. Don't even sign into your old online accounts. As far as everyone but the government is concerned, you'll have disappeared. If you're leaving an abusive family behind or avoiding the mafia, this is plenty, and you don't have to worry about being deported. Spend a few years as a waiter or construction worker being paid under the table and as long as you keep that up, you're even invisible from the less proactive parts of the government.

I'll be honest, faking my death seems dramatic and way too complicated for any situation i can come up with. I'd just do the disappear thing and leave it at that.